LAS VEGAS, Nevada (CNN) --Roy Horn of the glitzy Las Vegas duo Siegfried & Roy has been communicating with doctors and friends, his manager told reporters Sunday, two days after he was mauled onstage by one of the tigers in his show.

Horn, 59, remained in critical condition, which has not changed since the incident Friday night. Officials would not say whether he was on a ventilator or give any further details.

"The doctors are cautiously optimistic about his condition," manager Bernie Yuman said outside University Medical Center.

Yuman said the hopes of friends and physicians have been buoyed because Horn's condition has not worsened.

The accident happened Friday night about halfway through Siegfried & Roy's show at the MGM Mirage Hotel and Casino on the Las Vegas strip.

As the audience watched, a 7-year-old white tiger named Montecore lunged at Horn's neck and dragged him offstage.

Audience members said Horn looked like a rag doll in the tiger's mouth.

Crew members backstage sprayed a fire extinguisher at the big cat to force him to release his grip, a tactic they are trained to use in such an event, Mirage spokesman Alan Feldman said.

"There is no doubt at all that one of the factors in Roy's current condition -- the fact that he's alive -- was the fact that there was the availability of blood in this community," Feldman said.

The show's cast and crew also planned to hold a candlelight vigil outside the hospital Sunday night, Feldman said.

Horn, whose birthday was Friday, is the dark-haired member of Siegfried & Roy.

Roy Horn is shown in this file photo with one of his tigers.

Combining magic tricks with tiger stunts, Horn and Siegfried Fischbacher have performed as a duo on the Las Vegas strip for nearly 30 years.

The tiger was in quarantine Sunday night in accordance with state law, Feldman said, and a decision on what to do with the animal would wait until more was known about Horn's condition.

Yuman said Horn harbors no anger about the mauling.

"His feelings are that this has nothing to do with the tiger," Yuman said. "He's the last one to lay blame. You know, this is an unfortunate accident and after 30,000 live performances, one anomaly is indicative of the fact that his relationship with these animals is extraordinary and unprecedented."

The duo, Yuman said, has 63 exotic cats, none of which has ever displayed aggression.

A number of celebrities showed up at the hospital over the weekend to express their support. Jeffrey Katzenberg, one of the founders of the DreamWorks SKG studio, came by Sunday to visit his longtime friend.

Yuman said Katzenberg has just completed a digitally animated series based on Siegfried & Roy's animals, titled "Father of the Pride," which is due out next year.

The 210 crew members of the long-running show were told Saturday that the show was closed indefinitely, and Mirage managers suggested they consider other career options.

"Fortunately we may be able to place many of them at the MGM Grand," Feldman said. He said crew members may be able to find work with upcoming Las Vegas shows or at hotels scheduled to open soon.

Yuman said he was touched that crew members would plan a vigil for Horn despite the uncertainty over their employment and said it was evidence of the family atmosphere behind the scenes.

Those who had tickets for the Siegfried & Roy shows will be issued refunds, Feldman has said.